/Engine/Plugins/Runtime/NetworkPredictionExtras/Source/NetworkPredictionExtras/Public/MockRootMotionSimulation.h
Push the Sync state to the AnimInstance this is debatable - the simulation code doesn't need to call this, its really the concern of the driver (UMockRootMotionComponent) and not all potential root motion sources are going to want to set a pose.
void FinalizePose ( const [FMockRootMotionSyncState](API\Plugins\NetworkPredictionExtras\FMockRootMotionSyncState) * Sync, [UAnimInstance](API\Runtime\Engine\Animation\UAnimInstance) * AnimInstance )